Anti-double feed device



March w W KUP ANTI-DOUBLE FEED DEVICE Filed Jan. 2. 1968 Sheet of 3 FIGJ INVENTOR WILLIAM B. WALKUP,

ms ATTORNEY.

March 11, 1969 w. B. WALKUP 3,431,817

ANTI-DOUBLE FEED DEVICE Filed Jan- 2, 1968 Sheet off;

INVENTOR WILLIAM B. WALKUP,

BY Many-c. W

HIS ATTORNEY.

Mar ch 11, 1969 w. B. WALKUP 3,431,817

ANTI-DOUBLE FEED DEVI CE Filed Jan. 2, 1968 TO DC SUPPLY AND ACTION SWITCH INVENTOR WILLIAM B.WALKUP,

BY We. W- Y HIS ATTORNEY.

3,431,817 ANTI-DOUBLE FEED DEVICE William B. Walkup, Mattapoisett, Mass, assignor to General Electric Company, a corporation of New York Filed Jan. 2, 1968, Ser. No. 695,099 US. Cl. 89--12 Int. Cl. F41d 7/00 4 Claims ABSTRACT OF THE DISCLOSURE Background of the invention This invention relates generally to a device for clearing a high rate of fire automatic weapon in the event a cartridge or round is not extracted from the firing chamber and, more specifically, to means for sensing unextracted cartridges and mechanically actuating the gun clearing mechanism in time to prevent feeding a subsequent round to the gun battery station, with resultant jamming and damage to the weapon or feed system.

The US. military arsenal currently employs a number of very high rate of fire automatic weapons of the Gatling-gun variety, wherein a plurality of barrels are grouped for rotation about a common gun axis, e.g., as shown in the patent to Otto2,849,92l. In such guns a rotor assembly typically supports the barrels and includes longitudinally-extending tracks or ways for a number of bolt assemblies utilized to carry live cartridges or rounds to a gun battery station. After firing, the same bolt assemblies grip the spent cartridge casings and extract them for subsequent movement to a clearing station, as the rotor revolves about the common axis. Means for moving the bolt assemblies between the battery and clearing stations are usually provided in the form of rollers on the bolt assemblies engaged with an elliptical cam in a housing surrounding the rotor and supporting same for rotation, further means being provided to guide the live cartridges from a feeder mechanism to an opening in the housing where they are received by the bolt assemblies. Means have heretofore been provided (e.g., U.S. Patents 2,75 0,848 and 2,380,455) for double feed prevention in automatic weapons. Such mechanisms however, have left something to be desired in that they require extensive redesign of the gun operating or firing mechanism. This makes for a more costly and less reliable system. Also such systems usually operate solely on the control circuits (usually electrical) and do not mechanically operate to directly prevent succeeding cartridges from being fed to the battery station. In a machine gun type of weapon this dependency on electrical operation can have a detrimental effect on reliability.

Accordingly, it is a general object of the present invention to provide an improved, anti-double feed device for a high rate of fire automatic Weapon of the Gatling-gun variety.

A more specific object of this invention is to provide for such a weapon, a simplified, more reliable mechanical means for sensing unextracted cartridges in the battery station and further actuating the gun clearing mechanism to prevent resultant damage to the weapon due to jammmg.

3,431,817 Patented Mar. 11, 1969 Summary of the invention Briefly, in accordance with a disclosed embodiment of my invention I provide, for use with a high rate of fire automatic weapon of the Gatling-gun variety, an anti-double feed device in combination with a pivotable clearing sector member body portion comprising an arcuate segment of the gun housing, the device including sensing means comprising an elongated shaft rotatably supported from the housing, a lever arm mounted on one end of the shaft, and a cam mounted on the other end of the shaft. The lever arm projects radially inwardly of the gun axis, generally in the plane of the gun breech, the arm being located so as to clear the breech surface and open ones of the multiple gun battery locations, but be contacted by an unextracted cartridge casing remaining in any one of the barrel chambers or battery locations. On contact being made with an unextracted casing the lever arm rotates the shaft affixed thereto, which in turn causes the cam affixed at the other end of the shaft to rotate into engagement with the clearing body. The body of the clearing sector, operating as a continuation of the firing cam or path in the gun, in turn pivots so as to cause succeeding gun bolt assemblies to be maintained in the gun clearing station and not fed to the battery station.

The present invention, summarized above, will be more clearly understood from the following more detailed description of a preferred form thereof selected for illustration in the accompanying drawings, of which:

FIGURE 1 is a partial pictorial view of the breech and feed area of an automatic weapon of the Gatling-gun variety illustrating the invention;

FIGURE 2 is a split, partial cross-sectional view of the gun breech, simplified in detail for purposes of clarity, illustrating the position of the lever arm of the anti-double feed device during normal gun operation;

FIGURE 3 is a cross-section taken along line 3 of FIGURE 2;

FIGURE 4 is a view similar to FIGURE 2 illustrating the manner in which the improved device of my invention senses unextracted cartridges.

Description of the invention Referring now more s ecifically to FIGURE 1, indicated generally at 10 is the rotor of a high rate of fire automatic weapon of the Gatling-gun variety adapted to receive ammunition rounds or cartridges from a feeder mechanism (not shown). The weapon itself, which is basically unchanged by the incorporation of my invention, is more completely described in the aforementioned patent to Otto2,849,921. As shown it comprises a housing assembly 11 including an elliptical cam, the forward portion of which is partially shown at 12, formed in the outer periphery of the housing wall. The rotor assembly is provided 'with a plurality of longitudinally-extending ways or guides 14 which may be removably fastened to the rotor by bolts 15, or integrally formed in the main portion of the rotor body at the periphery thereof. A pair of ring bearings located generally at 1818 at either end of the housing support the rotor for rotation about the common gun axis. Movable in the tracks of the rotor are a plurality of bolt assemblies, indicated generally at 20, in FIG. 2. Typically, the bolt assemblies each contain a firing pin and firing pin spring (both not shown) mounted inside the body portion 22 of the bolt assembly. Projecting laterally of the body 22 is a shaft 24 supporting a roller 26 adapted to engage the elliptical cam 12 in the housing for moving the bolts in the tracks 14 to a forward battery station, as a result of the relative rotation between the rotor and the housing. In the firing station, cartridges or rounds R are inserted in openings 28 in the gun breech, or rear rotor wall 29 formed by the rearward ends of the gun barrels 30 flush with the wall surface, as seen in FIGURE 1. The elliptical cam 12 also operates to move the bolts 20 rearward toward a clearing station path or housing sector, indicated generally at 34 in FIGURE 2 and, more specifically, in FIGURE 4. Mounted adjacent an opening in the housing and juxtaposed between the housing and a suitable feeder mechanism (not shown) is a guide bar assembly indicated generally at 36. The guide bar assembly includes a pair of guide members one of which is indicated at 38, spaced longitudinally of the housing opening for directing live cartridges from the feeder mechanism to the relatively rotating and reciprocating bolt assemblies, whereby the cartridges are adapted to be gripped at their extractor rims at C (seen in FIG. 3) by suitable extractor lips (not shown) on the forward face of each bolt assembly 20. A cam surface 38a on the guide bar member 38 is also provided for directing spent cartridges overboard of the gun after they have been fired and extracted from the battery station or barrel breech opening 28, and moved to the clearing station at 34. It will be appreciated that the bolt assemblies do not remain in the clearing station but rather, after a spent cartridge is delivered overboard by the guide bar means 36 each bolt continues to rotate to accept a new or live cartridge from the feeder mechanism.

As stated the machine gun action mentioned above generally is no part of the present invention and for a more complete description of this modern version of the classic Gatling-gun configuration reference should be made to the aforementioned Otto patent entitled Gatling-gun. It will occasionally occur, however, that a round fails to extract from the battery station or the gun chamber at the breech end of the barrels. This may happen, for example, when a round R is fed in ahead of the extractor lips of the bolt assemblies, i.e., when feeder timing is oif with respect to gun rotor r.p.m. When this occurs, a round may be jammed into the chamber or breech opening 28 with no means of being extracted from the chamber after firing since it is not at that point being gripped by the bolt means. The bolt assemblies, however, are rotated clear of the battery station by the interaction of the rollers 26 and the cam 12 and return to the feed (clearing) position 34 where they pick up succeeding live rounds from the feeder mechanism. As a bolt and cartridge proceed to the battery station a jam will occur should the bolt attempt to feed a live cartridge into the chamber already occupied by a spent or jammed cartridge case.

To eliminate this circumstance and prevent resultant damage to the weapon the present invention is designed to provide a simple yet positive and reliable mechanical arrangement for preventing substantial damage to the weapon, and possibly to the vehicle carrying the weapon, whenever such a double feed occurs. To this end I have provided a pair of longitudinally spaced support members indicated at 40-40 in FIGURE 1 on an external surface of the guide bar assembly 36. Each support member 40 has a hole 41 drilled therein, both holes being at the same radial distance from the gun axis and aligned longitudinally of the gun. To accomplish mechanical actuation of the gun clearing mechanism in time to prevent occurrence of a double feed I provide sensing means for detecting whenever an unextracted shell is maintained in the chamber or breech opening 28, which opening should normally be cleared to accept a live cartridge on the next rotation of the particular gun bolt feeding that chamber. To this end, as shown in FIGURE 1, a sensor or lever arm member indicated at 42, is provided at one end of an elongated shaft 44 rotatably supported in the holes 41 of said support means. The lever arm 42 extends generally normal to the shaft axis at the end thereof, i.e., radially inwardly towards the gun axis as will be seen from FIGURE 2. The sensing arm 42 is so positioned that it is located beyond the firing position or angular location of each cartridge when in the breech. In other words, a cartridge in the battery station and ready to be fired, is fired and normally extracted from the breech opening 28 prior to that sector of the rotor reaching an angular position of the sensing arm, as shown by the dotted lines in FIG. 2. The path of a spent round R, as gripped by a bolt assembly, is elliptical until the case reaches the guide bar cam surfaces 38a, which then guide the case overhead. However, in the event the cartridge is unextracted, as shown in FIG. 4, the sensing arm 42 will be contacted by the case, causing the arm to pivot about the center line of the shaft, i.e., clockwise in FIGURE 4. At the other end of shaft 44 is a cam means indicated at 46, also secured to shaft 44 and adapted to be received in a detent portion 48 of a clearing sector assembly indicated generally at 50. The clearing sector comprises an elongated, arcuate body portion 51 having the same general curvature as the housing 11. The sector body is adapted to be pivoted about a pivot pin 52 at one end of the body. Normally, as seen in the lower portion of FIGURE 2, the cam 46 rides clear of the sector body detent 48. A torsion spring 53 (or other suitable means) is used to maintain the sector body in the outer position, i.e., where it is, effectively, out of the normal firing path comprising a rear dwell (generally circular) portion 54 of the elliptical cam path. As shown by the dotted lines in FIGURE 2, the rollers 26 leaving the elliptical cam 12 will be directed forwardly of the sector body and into the normal operating path, comprising dwell portion 54 and the beginning portion of cam 12, indicated by the groove 12a. It will be understood that the dwell portion of the normal operating (firing) path is essentially a circular slot in the inner surface of housing 11, at the clearing station 34, which operates to hold the bolt assemblies rearwardly of the gun until handing-off of spent cartridges and receipt of live cartridges is accomplished at the feeder opening, after which the main portion of the elliptical cam 12 (opening into slot 54 at 12a) takes over to provide the necessary reciprocating movement of the bolt assemblies.

On the other hand, if there is a failure-to extract, as shown in FIGURE 4, the resultant clockwise force exerted on shaft 44 pivots cam 46 against detent 48. This causes the clearing sector body portion 51 to pivot against the force of torsion spring 53. This positions the clearing rotor entrance ramp portion 51a so that it will capture the rollers 26 of the succeeding bolt assemblies, moving in the normal operating cam path (dwell portion 54) at this point, to cause the rollers to ride up into a clearing cam path or groove, indicated at 60. As will be clear from FIG. 4 as long as the clearing sector body portion is maintained in this position, all bolt assemblies follow clearing path 60 and are, thus, maintained at the rear of the gun housing. If the feeding action continues the live shells gripped by the bolt assemblies are merely circulated in the plate of the clearing station 34, being dumped overboard, unfired, after one complete revolution.

It may also be desirable, however, in order to save ammunition, to cease gun and feeder operation immediately on a failure to extract. Accordingly, I provide a spring operated plunger switch, indicated generally at 66, to effect a break in the main power circuit partially shown in FIG. 4, so as to de-energize the gun drive means (not shown). Thus, while switch 66 is depressed the circuit is closed between the trigger switch and a solenoid and relay, indicated by box 80, adapted to initiate cartridge feed and rotor operation by causing the rotor to be powered by a suitable drive motor (not shown) and cartridges to be fed to the gun. When the plunger 66a is released, by the pivoting action caused by an unextracted round, as shown in FIGURE 4, the circuit is broken, the rotor de-energized and, shortly thereafter, feed ceases. A more complete description of a typical Gatling-gun control circuit appears in the aforementioned Otto patent.

While a specific embodiment of the present invention is shown and described it will be obvious that other modifications and changes thereto as are within the scope of the claims will occur to those skilled in the art and it is intended that all such modifications and changes be included in the claims hereto.

What I claim and desire to secure by Letters Patent of the United States is:

1. In a machine gun of the Gatling type, wherein a housing supports a rotor body therein having barrels circularly grouped thereon for rotation about a common central axis, whereby successive ones of said barrels pass through a forward fixed battery station, and wherein rounds are fed successively to barrel chambers at said fixed battery station by a plurality of bolt assemblies for sequential firing in, and extraction from said chambers of said rounds, and subsequent removal thereof to a rearward clearing station, the improvement of means to prevent feeding of rounds to a barrel chamber having an unextracted round remaining therein subsequent to rotation of the barrel through said firing station, said improvement comprising:

sensing means adapted to be contacted by an unextracted round remaining in any barrel chamber when the barrel thereof is rotated out of the fixed battery station of the gun;

housing sector means movable between a first position,

wherein gun bolt assemblies are directed along a normal operating path, and a second position, wherein said bolt assemblies are directed to a gun clearing path;

actuating means in juxtaposition to said housing sector means and operably connected intermediate said sensing and said sector means; and

means for supporting said actuating and sensing means on the gun housing, whereby whenever said sensing means is contacted by an unextracted round said actuating means is operative to move said housing sector means from said first to said second position.

2. The invention according to claim 1, wherein said supporting means comprises an elongated shaft adapted to be rotatably mounted on the gun housing, said shaft extending longitudinally of the housing between the forward battery station and the rearward clearing station, and wherein said sensing means comprises an angular lever arm securely affixed to the end of said shaft and having a blade portion projecting inwardly of the housing in the general plane of the circularly arranged barrel chamber openings and through the radial elevation thereof.

3. The invention according to claim 2, and further including power switch means operable by said lever arm, when in contact with an unextracted round, for removal of rotational drive power from the rotor of said gun coincidental with movement of said housing sector means to said second position.

4. The invention according to claim 2, wherein said actuating means comprises a cam securely afiixed to the opposite end of said shaft from said lever arm and being rotatable inwardly of said housing, further wherein said housing sector means includes an elongated, generally arcuate, flat-sided body member conforming to the general curvature of the gun housing, said body member having biased mounting means at one end thereof for pivotally supporting said body member in the first position outwardly of a slot in said housing, said slot being in the normal operating path of said bolt assemblies, and further wherein said body member includes detent means on an outer periphery thereof, said cam being movable into contact with said detent means, on contact of said lever arm with an unextracted round, thereby to move said body member to the second position inwardly of said slot, said detent means maintaining said cam means in contact with said body member, whereby said bolt assemblies are maintained in said gun clearing path.

References Cited UNITED STATES PATENTS 6/1956 Boyer 89-138 X 9/1958 Otto 89-12 US. Cl. X.R. 89-33, 138 

